|Selective Single‐Site Pd−In Hydrogenation Catalyst for Production of Enhanced Magnetic Resonance Signals using Parahydrogen
|Year of Publication
|Burueva D, Kovtunov K, Bukhtiyarov A, Barskiy D, Prosvirin I, Mashkovsky I, Baeva G, Bukhtiyarov V, Stakheev A, Koptyug I
|Chemistry - A European Journal
Pd−In/AlO single‐site catalyst was able to show high selectivity (up to 98 %) in the gas phase semihydrogenation of propyne. Formation of intermetallic Pd−In compound was studied by XPS during reduction of the catalyst. FTIR−CO spectroscopy confirmed single‐site nature of the intermetallic Pd−In phase reduced at high temperature. Utilization of Pd−In/AlO in semihydrogenation of propyne with parahydrogen allowed to produce ≈3400‐fold NMR signal enhancement for reaction product propene (polarization=9.3 %), demonstrating the large contribution of pairwise hydrogen addition route. Significant signal enhancement as well as the high catalytic activity of the Pd−In catalyst allowed to acquire H MR images of flowing hyperpolarized propene gas selectively for protons in CH, CH and CH groups. This observation is unique and can be easily transferred to the development of a useful MRI technique for an in situ investigation of selective semihydrogenation in catalytic reactors.